The invention relates to a method and an apparatus for the automatic sorting of capsules, for example gelatin capsules used in the packaging of pharmaceutical products and the like. More particularly, the invention relates to a method and an apparatus for eliminating from a supply of capsules any which are dimensionally sub-standard, i.e. do not conform to the dimensional specifications, in particular with respect to the diameter. The sorting takes place at the point where a random supply of capsules is transformed into an ordered, sequential stream.
During the processing of capsules, for example hard gelatin capsules, either separately or in machinery which fills the capsules with some product and closes them thereafter, difficulties often arise in the supply of the capsules due to the fact that damaged or deformed capsules jam up the supply conduits. While the supply of capsules is subjected to a visual control prior to being placed in the storage container, damaged capsules nevertheless often escape detection by this visual control. Prior to being used by filling machinery and the like, the capsules must be placed into a sequential stream which is then transported to the processing stations through one or more conduits. If any of the capsules is deformed or oversized, such a capsule will hang up or jam in one of the channels. The removal of such a capsule entails a substantial expenditure of time and labor because it is usually not immediately obvious which of the capsules is damaged and has caused the stoppage. Moreover, the machinery is usually provided with several protective and safety devices which must first be removed in order to gain access to the conveyor tubes. Once the damaged or defective gelatin capsule is found, it must be removed by hand after which the safety devices must be reinstalled and only then can the machine be restarted. The extensive down-time and the expenditure of labor which this method entails is not economically feasible. Furthermore, the productivity of the machine is substantially reduced by its stoppage during the time required for removal of the defective capsules.